public class J08neicun {
    public static void main(String[] args) {
        int a = 4;
        String s1 = "abc";

        int[] arr = new int[10];
    }
}
class J08neicun2{
    public static void main(String[] args) {
        int a = 3;
        //传值
        int b = a;//复制了一份3，给b

        b = 100;
        System.out.println("a = " + a);//3


        System.out.println("======");
        //引用类型，复制的是地址
        //传址
        int[] arr1 = {1};
        int[] arr2 = arr1;

        arr2[0] = 100;
        // 100
        System.out.println("arr1[0] = " + arr1[0]);
    }
}